package leetcode;


import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
 * create by duanx 2022/2/7
 *
 * @classname: Test3
 * @author: duanx
 * @date: 2022/2/7 9:22
 **/
public class Test16 {

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str1;
        while ((str1 = br.readLine()) != null) {
            double m = Double.parseDouble(str1);
            double i = 0;
            while (i*i*i<m){
                i+=0.01;
            }
            System.out.println(String.format("%.1f", i));
        }
    }

}
